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ZnSeTe quantum dots (QDs) attract growing interest owing to their low threats to health and the environment. They are widely applied as emitters in displays and lighting devices. Previous findings have indicated that inorganic halides are excellent candidates for surface ligands on QDs. By incorporating inorganic halides during the synthesis process, the photoluminescence (PL) intensity and quantum yield (QY) of QDs can be significantly enhanced. However, the alteration of surface states in QDs induced by zinc halide modification and the mechanism of formation of trap-state radiative recombination processes have been less discussed. Herein, we proposed a synthesis strategy for ZnSeTe/ZnSe/ZnSeS/ZnS core/shell/shell/shell QDs modified with ZnCl2, and by comparing the morphology and elemental composition of QDs with different amounts of ZnCl2 added, we revealed the regulatory mechanism of nanocrystal growth in the presence of ZnCl2. QDs with modification of ZnCl2 exhibited broad yellow fluorescence, distinct from the intrinsic blue emission. Through spectroscopic and surface ligand analyses, we attributed this yellow emission to the intermediate state energy levels caused by the defects on the surface. Finally, we used the QDs with broad linewidth emission to fabricate a simple white-light-emitting diode (WLED). This work provided new insights into the role of inorganic ligands and the use of a single emitting material in solid-state lighting devices.
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Colloidal quantum dots (QDs) consist of an inorganic core and organic surface ligands. Surface ligands play a dominant role in maintaining the colloidal stability of QDs and passivating the surface defects of QDs. However, the original ligands introduced in the synthetic process of QDs cannot meet the requirements for diverse applications; therefore, ligand exchanges with functional ligands are mandatory. Understanding the ligand exchange process requires a comprehensive combination of the concepts and techniques of surface chemistry. In this Perspective, the ligand exchange process is discussed in detail. Specifically, we elaborate on the thermodynamics that can reveal the feasibility and mechanism of ligand exchange. It depicts a critical physical picture of the surface of QDs along with the following ligand exchange.
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Pyroptosis, a new mode of regulatory cell death, holds a promising prospect in tumor therapy. The occurrence of pyroptosis can trigger the release of damage-associated molecular patterns (DAMPs) and activate the antitumor immune response. Moreover, enhancing intracellular reactive oxygen species (ROS) generation can effectively induce pyroptosis. Herein, an integrated nanoplatform (hCZAG) based on zeolitic imidazolate framework-8 (ZIF-8) with Cu2+ and Zn2+ as active nodes and glucose oxidase (GOx) loading is constructed to evoke pyroptosis. GOx can effectively elevate intracellular hydrogen peroxide (H2O2) levels to regulate the unfavorable tumor microenvironment (TME). Cu2+ can be reduced to Cu+ by endogenous overexpressed GSH and both Cu2+ and Cu+ can exert Fenton-like activity to promote ROS generation and amplify oxidative stress. In addition, the accumulation of Cu2+ leads to the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT), thus resulting in cuproptosis. Notably, the outburst of ROS induced by hCZAG activates Caspase-1 proteins, leads to the cleavage of gasdermin D (GSDMD), and induces pyroptosis. Pyroptosis further elicits an adaptive immune response, leading to immunogenic cell death (ICD). This study provides effective strategies for triggering pyroptosis-mediated immunotherapy and achieving improved therapeutic effects.
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Glucose Oxidase , Piroptose , Espécies Reativas de Oxigênio , Microambiente Tumoral , Piroptose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Microambiente Tumoral/efeitos dos fármacos , Animais , Glucose Oxidase/metabolismo , Glucose Oxidase/química , Humanos , Camundongos , Cobre/química , Peróxido de Hidrogênio/química , Linhagem Celular Tumoral , Estruturas Metalorgânicas/química , Estruturas Metalorgânicas/farmacologia , Nanopartículas/química , Imunidade/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , ImidazóisRESUMO
Once nanoparticles enter into the biological milieu, nanoparticle-biomacromolecule complexes, especially the protein corona, swiftly form, which cause obvious effects on the physicochemical properties of both nanoparticles and proteins. Here, the thermodynamic parameters of the interactions between water-soluble GSH-CdSe/ZnS core/shell quantum dots (GSH-QDs) and human serum albumin (HSA) were investigated with the aid of labeling fluorescence of HSA. It was proved that the labeling fluorescence originating from a fluorophore (BDP-CN for instance) could be used to investigate the interactions between QDs and HSA. Gel electrophoresis displayed that the binding ratio between HSA and QDs was â¼2:1 by direct visualization. Fluorescence resonance energy transfer (FRET) results indicated that the distance between the QDs and the fluorophore BDP-CN in HSA was 7.2 nm, which indicated that the distance from the fluorophore to the surface of the QDs was â¼4.8 nm. Fluorescence correlation spectroscopy (FCS) results showed that HSA formed a monolayer of a protein corona with a thickness of 5.5 nm. According to the spatial structure of HSA, we could speculate that the binding site of QDs was located at the side edge (not the triangular plane) of HSA with an equilateral triangular prism. The elaboration of the thermodynamic parameters, binding ratio, and interaction orientation will highly improve the fundamental understanding of the formation of protein corona. This work has guiding significance for the exploration of the interactions between proteins and nanomaterials.
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Compostos de Cádmio , Coroa de Proteína , Pontos Quânticos , Humanos , Transferência Ressonante de Energia de Fluorescência , Coroa de Proteína/metabolismo , Albumina Sérica/química , Compostos de Cádmio/química , Espectrometria de Fluorescência , Albumina Sérica Humana/metabolismo , Pontos Quânticos/química , Ligação ProteicaRESUMO
Nanocatalytic therapy (NCT) has made great achievements in tumor treatments due to its remarkable enzyme-like activities and high specificity. Nevertheless, the limited types of nanozymes and undesirable tumor microenvironments (TME) greatly weaken the therapeutic efficiency. Developing a combination therapy integrating NCT and other strategies is of great significance for optimal treatment outcomes. Herein, a AuPt-loaded Cu-doped polydopamine nanocomposite (AuPt@Cu-PDA) with multiple enzyme-like activities was rationally designed, which integrated photothermal therapy (PTT) and NCT. The peroxidase (POD)-like activity of AuPt@Cu-PDA can catalyze hydrogen peroxide (H2O2) into ·OH, and the catalase (CAT)-mimic activity can decompose H2O2 into O2 to alleviate hypoxia of TME, and O2 can be further converted into toxic ·O2- by its oxidase (OXD)-mimic activity. In addition, Cu2+ in AuPt@Cu-PDA can effectively consume GSH overexpressed in tumor cells. The boosting of reactive oxygen species (ROS) and glutathione (GSH) depletion can lead to severe oxidative stress, which can be enhanced by its excellent photothermal performance. Most importantly, the accumulation of Cu2+ can disrupt copper homeostasis, promote the aggregation of lipoylated dihydrolipoamide S-acetyltransferase (DLAT), disrupt the mitochondrial tricarboxylic acid (TCA) cycle, and finally result in cuproptosis. Collectively, photothermal and photoacoustic imaging (PTI/PAI)-guided cuproptosis-enhanced NCT/PTT can be achieved. This work may expand the application of nanozymes in synergistic therapy and provide new insights into cuproptosis-related therapeutic strategies.
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Apoptose , Cobre , Peróxido de Hidrogênio , Diagnóstico por Imagem , Glutationa , Terapia Fototérmica , Microambiente Tumoral , Linhagem Celular TumoralRESUMO
Particle size might affect the inhibition behaviors of gold nanoparticles (AuNPs) on enzyme activity by influencing the density of binding sites (ρ), the association constant (Ka), the steric hindrance of enzymes by AuNPs, the binding orientations of the enzyme on AuNPs, as well as the structural changes of enzymes. In previous studies, the effects of the above-mentioned factors, which could not be ignored in the applications of enzymatic electrochemistry, were often overshadowed by the effects of surface area. In order to study the size effect on the inhibition types and inhibitory ability of enzymes by AuNPs, we investigated the inhibition behaviors of chymotrypsin (ChT) by AuNPs with three different sizes (D1-AuNCs, D3-AuNPs, and D6-AuNPs) under the same surface area concentration. The results showed that both of the inhibition types and the inhibition ability varied with the particle size of AuNPs. D1-AuNCs inhibited ChT noncompetitively, while D3/D6-AuNPs inhibited ChT competitively. Contrary to the common sense, D6-AuNPs showed a weaker inhibitory ability than D3-AuNPs. By means of zeta potential, agarose gel electrophoresis, isothermal titration calorimetry, synchronous fluorescence spectroscopy, and circular dichroism, the mechanism of the weak inhibitory ability of D6-AuNPs was found to be the standing binding orientation caused by the small curvature. This work had certain guiding significance for the biosafety of AuNPs, the development of nanoinhibitors, as well as the applications of AuNPs in enzymatic electrochemistry.
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Nanopartículas Metálicas , Ouro , Sítios de Ligação , Tamanho da Partícula , Espectrometria de FluorescênciaRESUMO
The fibrillation process of human insulin (HI) is closely related to the therapy for type II diabetes (T2D). Due to changes in the spatial structure of HI, the fibrillation process of HI takes place in the body, which leads to a significant decrease in normal insulin levels. L-Lysine CDs with a size of around 5 nm were synthesized and used to adjust and control the fibrillation process of HI. ThT fluorescence analysis and transmission electron microscopy (TEM) characterization of the CDs showed the role of HI fibrillation from the perspective of the kinetics of HI fibrillation and regulation. Isothermal titration calorimetry (ITC) was used to explore the regulatory mechanism of CDs at all stages of HI fibrillation from the perspective of thermodynamics. Contrary to common sense, when the concentration of CDs is less than 1/50 of the HI, CDs will promote the growth of fibres, while a high concentration of CDs will inhibit the growth of fibres. The experimental results of ITC clearly prove that different concentrations of CDs will correspond to different pathways of the combination between CDs and HI. CDs have a strong ability to combine with HI during the lag time, and the degree of combination has become the main factor influencing the fibrillation process.
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Diabetes Mellitus Tipo 2 , Pontos Quânticos , Humanos , Lisina , Pontos Quânticos/química , Carbono/química , Diabetes Mellitus Tipo 2/tratamento farmacológico , InsulinaRESUMO
Fibrillation process of human insulin (HI) is closely related to type 2 diabetes (T2D). In the present work, Carbon Polymer Dots (CPDs) was synthesized by Bodipy to control the process of insulin fibrillation. The inhibition process of insulin fibrillation with the existence of CPDs was completed investigated. The hydrophobic interaction of CPDs and insulin was used to inhibit the change of insulin's secondary structure in the lag phase and growth period. ThT fluorescence analysis and transmission electron microscopy (TEM) characterization of the CPDs were used to explore the kinetics of insulin fibrillation and regulation process by CPDs. Isothermal titration calorimetry (ITC) was applied to explore the regulatory mechanism by CPDs at all stages of the insulin fibrillation process. ThT was used to complete the chemical modification of CPDs by Friedel-Crafts alkylation, which made the CPDs maintain the characteristics of photothermal effect and also obtain the ability to bind specifically to the fibers. Finally, the process of defibrillation of human insulin fibers under the Near-infrared light's irradiation was realized. In this work, we clarified the mechanism of the regulation process by Bodipy CPDs and made CPDs able to defibrillate the insulin fibers by chemical modification.
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Diabetes Mellitus Tipo 2 , Polímeros , Humanos , Polímeros/farmacologia , Polímeros/química , Carbono/química , Insulina/química , CalorimetriaRESUMO
Colloidal quantum dots (QDs) are a class of representative fluorescent nanomaterials with tunable, bright, and sharp fluorescent emission, with promising biomedical applications. However, their effects on biological systems are not fully elucidated. In this work, we investigated the interactions between QDs with different surface ligands and different particle sizes and α-chymotrypsin (ChT) from the thermodynamic and kinetic perspectives. Enzymatic activity experiments demonstrated that the catalytic activity of ChT was strongly inhibited by QDs coated with dihydrolipoic acid (DHLA-QDs) with noncompetitive inhibitions, whereas the QDs coated with glutathione (GSH-QDs) had weak effects. Furthermore, kinetics studies showed that different particle sizes of DHLA-QDs all had high suppressive effects on the catalytic activity of ChT. It was found that DHLA-QDs with larger particle sizes had stronger inhibition effects because more ChT molecules were bound onto the surface of QDs. This work highlights the importance of hydrophobic ligands and particle sizes of QDs, which should be considered as the primary influencing factors in the assessment of biosafety. Meanwhile, the results herein can also inspire the design of nano inhibitors.
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Pontos Quânticos , Interações Hidrofóbicas e Hidrofílicas , Glutationa , LigantesRESUMO
InP quantum dots (QDs) attract growing interest in recent years, owing to their environmental advantages upon applications in display and lighting. However, compared to Cd-based QDs and Pb-based perovskites, the synthesis of InP QDs with high optical quality is relatively more difficult. Here, we established a mid-synthetic modification approach to improve the optical properties of InP-based QDs. Tris(dimethylamino)phosphine ((DMA)3P) and indium iodide were used to prepare InP QDs with a green emission (â¼527 nm). By introducing zinc halides (ZnX2) during the mid-synthetic process, the photoluminescence quantum yield (PLQY) of the resulting InP/ZnSeS/ZnS core/shell/shell QDs was increased to >70%, and the full-width-at-half-maximum (FWHM) could be narrowed to â¼40 nm. Transmission electron microscopy clearly showed the improvement of the QDs particle size distribution after introducing ZnX2. It was speculated that ZnX2 was bound to the surface of QDs as a Z-type ligand, which not only passivated surface defects and suppressed the emission of defect states but also prevented Ostwald ripening. The InP cores were also activated by ZnX2, which made the growth of the ZnSeS shell more favorable. The photoluminescence properties started to be improved significantly only when the amount of ZnX2 exceeded 0.5 mmol. As the amount increased, more ZnX2 was distributed around the QDs to form a ligand layer, which prevented the shell precursor from crossing the ligand layer to the surface of the InP core, thus reducing the size of the InP/ZnSeS/ZnS QDs. This work revealed a new role of ZnX2 and found a method for InP QDs with high brightness and low FWHM by the mid-synthetic modification, which would inspire the synthesis of even better InP QDs.
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As a new two-dimensional (2D) material, transition metal carbides and nitrides (MXenes) have attracted much attention because of their excellent physical and chemical properties. In recent years, MXenes have been widely applied in the biological field due to their high biocompatibility, abundant surface groups, good conductivity, and photothermal properties. Here, the main synthesis methods of MXenes and the analysis of the advantages and disadvantages of each method are presented in detail. Then, the latest developments of MXenes in the biological field, including biosensing, antibacterial activity, reactive oxygen species (ROS) and free radical scavenging, tissue repair and antitumor therapy are comprehensively reviewed. Finally, the current challenges and future development trends of MXenes in biological applications are discussed.
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Antibacterianos , Metais , Antibacterianos/farmacologia , Condutividade Elétrica , Compostos Orgânicos , Espécies Reativas de OxigênioRESUMO
Three common types of reversible inhibitors, namely competitive, noncompetitive and uncompetitive inhibitors, were designed and constructed by using enzymes with different surface charges and gold nanoparticles with different surface ligands and particle sizes. To our knowledge, it is the first time that an uncompetitive nano inhibitor has been discovered.
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Inibidores Enzimáticos , Nanopartículas Metálicas , Cinética , Inibidores Enzimáticos/farmacologia , Ouro/farmacologia , Ligantes , Ligação Competitiva , Enzimas/metabolismoRESUMO
Cu-modified nanoparticles have been designed to mimic peroxidase, and their potent antibacterial and anti-biofilm abilities have been widely investigated. In this study, novel core-shell polydopamine (PDA)/Cu4(OH)6SO4 crystal (PDA/Cu) nanometer rods were prepared. The PDA/Cu nanometer rods show similar kinetic behaviors to chloride-activated peroxidases, exhibit excellent photothermal properties, and are sensitive to the concentrations of pH values and the substrate (i.e., H2O2). PDA/Cu nanometer rods could adhere to the bacteria and catalyze hydrogen peroxide (H2O2) to generate more reactive hydroxy radicals (â¢OH) against Staphylococcus aureus and Escherichia coli, Furthermore, PDA/Cu nanometer rods show enhanced catalytic and photothermal synergistic antibacterial activity. This work provides a simple, inexpensive, and effective strategy for antibacterial applications.
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Three-dimensional (3D) self-assembled quantum dot (QD) aerogels have attracted attention due to the combined properties of both QDs and porous materials. However, the difficulty and complexity of structural composition control limit the practical application of 3D self-assembled QDs. Hence, convenient, available and multifunction QD aerogels need to be explored to promote broader practical applications. Herein, we propose a universal and facile self-assembly method of copper indium selenium (CISe) QD aerogels based on coordination interaction between Zn2+ and carboxyl. Both experiments and Monte Carlo simulations indicate that QDs are aggregated into oligomers by Zn2+, and then the oligomers are gradually interconnected to each other to form a 3D network as the concentration of Zn2+ increases. Moreover, Zn2+-induced 3D self-assembled aerogel could be depolymerized by EDTA reversibly. In combination with CISe QDs, Zn-CISe aerogel has been successfully applied in green pollution-free environment-friendly anti-counterfeiting and encryption systems.
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In recent years, the development and application of integrated probes for theranostics have attracted more and more attention. However, few biological probes can meet the needs of in vivo and in vitro long-term near-infrared imaging and photodynamic therapy, especially with a certain subcellular organelle targeting ability. Here, 2-chlorophenothiazine as a pharmacophore is linked to the mitochondrial targeting group pyridine cation through an alkyl chain, which is further linked to triphenylamine-based aggregation-induced emission groups to obtain two aggregation-induced emission luminogens (AIEgens). Only the presence or absence of thiophene causes two AIEgens to exhibit different structure-oriented characteristics. Although they are different with respec to mitochondrial targeting, cellular imaging, and cytotoxicity, they all have excellent in vivo and in vitro long-term near-infrared imaging and photodynamic therapy capabilities.
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Fotoquimioterapia , Corantes Fluorescentes , Mitocôndrias , Imagem Óptica , Fotoquimioterapia/métodos , TiofenosRESUMO
Tumor targeting therapy and photodynamic therapy are effective anti-cancer therapies. Their research progress has attracted wide attention and is one of the focuses of anti-cancer drug research and development. The design and synthesis of multifunctional organic phototheranostic agents for superior image-guided diagnosis and phototherapy play an increasingly positive role in cancer diagnosis and treatment. Herein, F16M and CyM were obtained through functional design from cyanine and F16. Physicochemical characterization and biological application results showed that CyM is a multifunctional organic biological probe, which can realize intracellular multichannel (green, yellow, red, and NIR) imaging, pH detection, and mitochondrial-targeted photodynamic therapy. As an organic phototheranostic agent, it could not only realize near-infrared imaging and photodynamic therapy in vivo and in vitro but also has excellent biocompatibility and good guiding significance for the development of multichannel imaging and mitochondrial-targeting photodynamic therapy.
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Técnicas Biossensoriais , Nanopartículas , Fotoquimioterapia , Corantes , Concentração de Íons de Hidrogênio , Fotoquimioterapia/métodos , FototerapiaRESUMO
A boron-dipyrromethene (BODIPY)-based fluorescent probe, BDP-CN, was synthesized in this work. It had a fluorescence emission maximum at 512 nm and a high quantum yield (48%). As evidenced by agarose gel electrophoresis and liquid chromatography-mass spectrometry, it could realize the fluorescent labeling of human serum albumin (HSA) through a thiol-cyanimide addition. Interestingly, f-HSA, defined as HSA labeled by BDP-CN, had an even higher quantum yield (77%). In addition, BDP-CN would not affect the secondary structure of HSA. Based on the successful formation of f-HSA, it was further applied to study the interactions with nanoparticles. The fluorescence quenching of f-HSA by dihydrolipoic acid-coated gold nanoclusters (DHLA-AuNCs) obeyed a dynamic mechanism, consistent with the intrinsic fluorescence quenching of HSA by DHLA-AuNCs. The association constant Ka between f-HSA and DHLA-AuNCs at 298 K was 1.5 × 105 M-1, which was the same order of magnitude as that between HSA and DHLA-AuNCs. Moreover, the interactions of f-HSA with glutathione-coated gold nanoclusters confirmed that the labeled fluorescence could replace the intrinsic fluorescence to monitor the interactions between proteins and nanoparticles. By this method, strong fluorescence ensures better stability and reproducibility, excitation at a longer wavelength reduces the damage to the proteins, and covalent conjugation with cysteine residues eliminates the inner filter effects to a great extent. Therefore, the strategy for the fluorescent labeling of HSA can be expanded to investigate a broad class of nanoparticle-protein interactions and inspire even more fluorescent labeling methods with organic dyes.
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Nanopartículas Metálicas , Albumina Sérica Humana , Corantes Fluorescentes , Ouro/química , Humanos , Nanopartículas Metálicas/química , Reprodutibilidade dos Testes , Albumina Sérica Humana/química , Espectrometria de Fluorescência/métodos , Compostos de SulfidrilaRESUMO
Multifunctional probes with high utilization rates have great value in practical applications in various fields such as cancer diagnosis and therapy. Here we have synthesized two organic molecules based on merocyanine. They can self-assemble in water to form â¼1.5 nm nanoparticles. Both of them have good application potential in fluorescent anticounterfeit printing ink and pH detection. More importantly, they have excellent mitochondrial targeting ability, intracellular red light and near-infrared dual-channel imaging ability, strong antiphotobleaching ability, and in vivo and in vitro near-infrared imaging capabilities, showing superior chemotherapy capabilities and biocompatibility in the 4T1 tumor-bearing mouse model.
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Antineoplásicos/uso terapêutico , Benzopiranos/uso terapêutico , Indicadores e Reagentes/uso terapêutico , Indóis/uso terapêutico , Nanopartículas/uso terapêutico , Neoplasias/tratamento farmacológico , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Benzopiranos/química , Linhagem Celular Tumoral , Fraude/prevenção & controle , Humanos , Concentração de Íons de Hidrogênio , Indicadores e Reagentes/química , Indóis/química , Tinta , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Nanopartículas/química , Neoplasias/metabolismo , Espécies Reativas de Oxigênio/metabolismoRESUMO
Deep-red (λem â¼ 710 nm) thiolated Ag@Au nanoclusters with a quantum yield of â¼18% were rapidly (â¼12 min) prepared in aqueous solutions. The effects of pH and silver ions were demonstrated. The surface modification further resulted in nanoclusters with a quantum yield of â¼38%, the highest value ever reported for water-soluble red Au nanoclusters. This will highly facilitate their applications in sensing, bioimaging, etc.
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Carbon dots (CDs) have been widely used in recent years because of their excellent water solubility and abundant surface functional groups. However, compared with quantum dots or biological probes, the quantum yield of CDs is lower, and the fluorescence mainly concentrated in the blue-green range, which significantly limits the biological applications of CDs. Heteroatoms doping is the most common method to improve the luminescence of CDs. In this work, nitrogen and sulfur co-doped luminescent CDs were successfully synthesized by microwave assisted method using glutathione (GSH) and p-phenylenediamine (PPD) as raw materials. It can emit bright green fluorescence in ethanol solution, and the maximum emission wavelength is 535 nm when excited at 374 nm, and the absolute quantum yield is as high as 63%. Iron ion (Fe3+) can interact with the functional groups on the surface of the CDs to form CDs/Fe3+, which is a non-fluorescence complex, and Fe3+ can be reduced to ferrous ion (Fe2+). In other words, the reaction mechanism of CDs and Fe3+ is a combination of dynamic quenching and static quenching. The fluorescence of CDs quenched by Fe3+ can be restored by thiol, because there is a stronger binding force between sulfhydryl (-SH) on the surface of thiol and Fe3+, which enables CDs to be released. In addition, the CDs has good biocompatibility and stability, indicating that it has excellent potential in bioimaging. This discovery will expand the application of CDs in the fields of biosensing and imaging.